Engine-stop.



PATENTED FEB. 17', 1903..

W. H. DUNN. ENGINE STOP.

APPLICATION FILED rm. 3, 1902.

s SHEETS-SHYEET 1.

N0 MODEL.

c -bwzul'oi WCZCL'WILJECZ? w LIL o. W n

' Ko.'7 20,683. PATENTED 12513.17;19 05.

W. H. DUNN.

ENGINE STOP.

APPLICATION FILED FEB. 3, 1902.

3 SHEETS-SHEET 2.

30 MODEL.

Wihwooeo cams PETER! 60.. mmo umo wunmumu. n. C.

4 PATENTBD-PEB. 17, 1903. W. H. DUNN.

ENGINE STOP APPLICATION FILED FEB. s, 4902.

- amnmtoz Wilda/z o Der/2oz o UNITED STATES PATENT OFFICE.

WILLIAM H. DUNN, OF WALLINGFORD, CONNECTICUT.

ENGINE-STOP.

SPECIFICATION forming part of Letters Patent No. 720,683, dated February 1'7, 1903.

Application filed I'ebruary: 3, l902. $erial No. 92,440. (No model.)

To aZZ whom it 71mg concern:

Be it known that I, WILLIAM H. DUNN, a citizen of the United States, residing at Wallingford, in the county of New Haven and State of Connecticut, have invented certain new and useful Improvements in Engine- Stops; and I do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same.

This invention belongs to electrically-controlled stop mechanism for engines and machinery capable of being controlled from a distant point through the intervention of a H stop mechanism of this type is most generally spring or weight actuated mechanism.

used in connection with a throttle-valve, and

the present specification contemplates such application, although the invention is of a much broader scope.

The invention has for its primary object to maintain an alarm-circuit at all times and under all conditions, so that a signal may be sent in from any pointor points of the system to the attendant in charge of the mechanism to which the stop mechanism is applied.

The invention also aims to provide a novel means for automatically interrupting the alarm-circuit at or about the same instant the throttle is closed or the mechanism thrown out of action, thereby preventing the continuous ringing of the bell and obviating'the personal attention usually required to break the circuit.

The invention further aims to combine with the stop mechanism means for automatically operating the switch to throw the alarm-circuit into condition for operation upon pressing the button to close the circuit when it is required to throw the stop mechanism into action, thereby guarding against oversight of the attendant to close the switchwhen the throttle is open or the machine is running.

For a full description of the invention and the merits thereof and also to acquire a knowledge of the details of construction of the means for effecting the result reference is to be had to the following description and drawings hereto attached. 7

While the essential and characteristic features of the invention are susceptible of modification, still thepreferred embodiment of the invention is illustrated in the accompanying drawings, in which Figure 1 is a detail view showing the application of the invention. Fig. 2 is a perspective view of the stop mechanism, the cover of the casing beingthrown open, so as to expose the working parts. Fig. 3 is a detail perspective view of the indicator and mechanism for automatically throwing the switch. Fig. 4 is a diagrammatic view.

Corresponding and like parts are'referred to inthe following description and indicated in all the views of the drawings by the same reference characters. I

The working parts of the stop mechanism are compactly arranged and housed within a casing 1, conveniently located to the throttlevalve or other mechanism to be controlled or thrown out of action from a distant point by closing an electric circuit. The power-actuated shaft 2 is provided at one end with a drum 3 and gear-wheel 4, the latter being connected in any selected way with the stem of the throttle-valve or convenient part of the mechanism to be controlled by means found most advantageous for the purpose. The shaft 2 may be controlled either by a spring or weight, or by both, and is provided with a wheel 5, having an oftstanding rim toothed at its outer edge, as shown at 6. The weight or spring is held wound by means of a pawl 7 which is positioned to engage with a tooth 6 of the ratchet-wheel 5. An arm 8 is connected with the pawl 7, so as to move the ratchet-wheel 5, thereby permitting the weight or spring to turn the drum 3 and close the throttle-valve or throw the mechanism to which the stop is applied out of action.

A threaded stem 11 projects from one end of the shaft 2 in line with the axis thereof and receives a nut 12, movable back and forth upon said stem, according to the direction of rotation of the shaft 2. A lifter 13 is provided at the outer end of the threaded stem 11, and consists of'a shouldered cam secured upon the threaded stem 11 and is weighted at its lower end, so as normally to occupy a vertical position, and is provided near its upper end with an offstanding pin 16 for engagement with the shoulder of the lifter 13, whereby the index is turned from a perpendicular position, thereby apprising the attendant that the weight or spring is suffi ciently wound and that the throttle-valve or starting mechanism has been moved to a point to admit of full power. As the shaft 2 is rotated the nut 12 moves outward upon the threaded stem 11 and imparts a like movement to the index 15 and brings the offstanding part 16 into the path of the lifter, whereby the index is elevated at its working end, as will be readily comprehended.

A shaft 17, journaled ata right angle to the shaft 2, is provided with an electrically-insulated part 18, and this shaft, in connection with spring-blades 19 and 20, constitutes an electric switch for controlling the alarm-circuit in a manner presently to be explained. A crank-arm 21 at the outer end of the shaft 17 is connected by a pitman 22 with a lever 23, which in turn cooperates with the nut 12, so as to eltect automatic rotation of the shaft 17 when starting or stopping the machine with which the invention cooperates. When the throttle is open or the engine running, the insulated portion 18 of the shaft 17 is withdrawn from under the blades 19 and 20, the nut 12 occupies the outermost position upon the threaded stem 11, and the outer end of the index 15 is elevated; but when the throttle is closed or the machine out of action the insulated portion 18 of the shaft 17 comes beneath the blades 19 and 20, the index 15 hangs perpendicular, and the nut 12 is near the inner end of the threaded stem 11.

The electric circuit for releasing the weight or spring whereby the stop mechanism is actuated includes an electromagnet 24, metal plates 25 and 26, lead-wires 27 and 28, conductors 36 and 37, and an electric battery 29. A push-button or circuitcloser 30 and an electric bell 31 are included in the circuit. The terminals of the wire of the electromagnet 24 are connected with the plates 25 and 26, and the leads 27 and 28 are likewise connected with said plates. The blade 19 is electrically connected with the plate 26, whereas the blade 20 has an arm 32 connected therewith. An arm 33 is connected by wire 34 with one binding-post of an electric bell 31, the other binding-post of the bell being connected by wire 36 with one pole of the battery or electric generator 29 and by wire 28 with the push-button 30. The lead 28 connects the push-button 30 with the plate 25. The lead 27 connects the plate 26 with the opposite pole of the battery 29. The opposing ends of the parts 32 and 33 are spaced apart and curved and are adapted to be bridged by the pawl 7, which is adapted to complete the circuit through said parts 32 and 33 when the arm 8 has been released and acted upon by the spring 9. The armature 38 is supported by one end of a lever 39, the opposite end of said lever being adapted to engage with the arm 8 and hold the pawl 7 in engagement with a tooth of the ratchetwheel 5 against the action of the spring 9. A circuit-closing arm 40 projects from the armature or lever 39 and is adapted to coopcrate with a companion arm 41, connected with the plate 26. These arms 40 and 41 are held apart when the armature 38 is not attracted; but when the electromagnet is energized and the armature attracted the arm 40 is moved toward the arm 41, and the electric circuit is closed through said arms. When the throttle-valve is open or the machine running, the arms 40 and 41 stand apart, the pawl 7 is in engagement with a tooth of the ratchet-wheel 5, and the blades 19 and 20 are in electric connection through the shaft 17. Upon closing the circuit through the button 30 the current passes through the lead-wire 28, electromagnet 24, lead wire 27 to battery. The current passing through the electromagnet vitalizes the same and attracts the armature 38, thereby releasing the arm 8 and pawl 7, and the spring 9 being no longer held under restraint withdraws the pawl 7 from engagement with the ratchet-wheel 5 and permits the weight or spring to rotate the drum 3 and to close the throttle-valve or to throw the machine out of action. While the arm 8 is released, the pawl 7 closes the circuit by bridging the space formed between the terminals of the plates 32 and 33, and the bell 31 being included in the circuit thus closed rings continuously during the operation of seating the valve. This circuit is as follows: from battery 29 through lead 27, plate 26, blade 19, shaft 17, blade 20, part 32, pawl 7, part 33, lead-wire to hell 31, thence to battery through lead-wire 28. Just prior to the seating of the throttle-valve for the stopping of the machine the insulation 18 is brought beneath the blades 19 and 20, thereby interrupting the circuit and causing the bell to cease ringing. The alarm-circuit may be used to transmit a signal from a remote point to the engineer or attendant in charge of the engine by pressing the button 30. It must be remembered that when the throttlevalve is seated and the insulation 18 is beneath the blades 19 and 20 the pawl 7 electrically connects the parts 32 and 33. Hence when pressing the button 30 to close the alarm-circuit to send in a signal to the engineer or other attendant the current is as follows: from battery 29 through lead-wire 27 to plate 26, to electromagnet 24, to plate 25, to lead-wire 28, button 30, back to the battery. Simultaneously with energizing the electromagnet 24 the armature 38 is attracted and closes the alarm-circuit through the points and 41, this circuit being as follows: from battery through leadwire 27 to plate 26, to arm 41, arm 40, armature-lever 39, post 10, spring 9, pawl 7, part 33, lead-Wire 35, bell 31, thence back to the battery through leadwire 28. When the throttle-valve is again opened, the stop mechanism is reset by rotation of the shaft 17, so as to withdraw the in sulation 18 from beneath the blades 19 and 20, the weight or spring being wound as the valve is unseated, theindexindicatiug danger when the valve is sufficiently open.

Having thus described the invention, what is claimed as new is- 1. In an engine-stop, and in combination with the actuating mechanism, and a detent for holding the actuating mechanism in check, an electric circuit including an alarm mechanism, and a releasing mechanism for cooperation with the said detent, and an electric switch automatically operated by means of the aforesaid actuating mechanism to throw the alarm-circuit into and out of action, substantially as set forth.

2. In an engine-stop, and in combination with the actuating mechanism, and a detent therefor, an electric circuit including an alarm, a releasing mechanism for the detent, and a switch, and means for establishing the alarm-circuit by means of the detent when interrupted by means of the switch, substantially as set forth.

3. In an engine-stop, and in combination with the actuating mechanism and a detent therefor, an electric circuit including an alarm, and an electric releasing device for the detent, contacts 40 and 41 adapted to be closed when the electromaguet of the releasing mechanism is energized, and other contacts 32 and 33 adapted to be closed by the detent when released from the actuating mechanism, substantially as set forth.

4:- In an engine-stop, and in combination with the actuating mechanism a detent therefor, and an electric circuit including a releasmatically-actuating means for said switch comprising a threaded stem, a nut movable on said threaded stem, and connections between said nut and the movable part of the electric switch for throwing the latter, substantially as specified.

6. In an engine-stop, and in combination with the actuating mechanism, detent therefor, and electrically controlled releasing mechanism for the detent comprising an electric switch, means for automatically throwing the switch, and an index operated by means of the said actuating mechanism, substantially as set forth.

7. In combination, actuating mechanism, a detent therefor, electrically-controlled releasing mechanism for the detent, an electric switch, operating means for said switch includinga threaded stem and nut, a weighted index loosely mounted upon the threaded stem and movable thereon by means of the said nut, and a lifter connected to the said.

threaded stem for operating the index, substantiallyas set forth.

In testimony whereof I affix my signature in presence of two witnesses.

WILLIAM H. DUNN. [L. s.'] Witnesses:

O. H. BROWN, B. H. WOODING. 

